BEIJING (AP) Bulgaria's Plamen Konstantinov returned to his volleyball team after clearing up rumors of doping.

Konstantinov missed his team's first four matches to travel back to Bulgaria to take a test he hoped would prove he was clean. The Bulgarian anti-doping commission reported that Konstantinov's sample was negative.

Konstantinov had five points in Bulgaria's 3-1 victory over Venezuela on Monday. With the victory, the Bulgarians were 3-2 after preliminary pool play.

"Plamen is a very important part of the team. If you have an engine and you take out a piece of that engine, you need time for it to start working correctly," Bulgarian coach Evgeni Ivanov said. "Plamen is the right piece of this engine and (his return) is important for us to get confident before the quarterfinals."

The Bulgarians had to wait for the conclusion of Monday's matches to learn their opponent for the quarterfinals on Wednesday.